Introduction

Introduction

Important submission note: For full credit,

• Submit with Phases 1 & 2 complete by 4/18/21 (worth 4 pts).
• Submit with Phases 3 & 4 complete by 4/29/21

You will get two extra credit points for submitting the entire project by 4/27/21.

You may work with one other partner for the entire project.

In this project, you will create a tower defense game called Ants Vs. SomeBees. As the ant queen, you populate your colony with the bravest ants you can muster. Your ants must protect their queen from the evil bees that invade your territory. Irritate the bees enough by throwing leaves at them, and they will be vanquished. Fail to pester the airborne intruders adequately, and your queen will succumb to the bees' wrath. This game is inspired by PopCap Games' Plants Vs. Zombies.

This project combines functional and object-oriented programming paradigms, focusing on the material from Chapter 2.5 of Composing Programs. The project also involves understanding, extending, and testing a large program.

Download starter files

The ants.zip archive contains several files, but all of your changes will be made to ants.py.

• ants.py: The game logic of Ants Vs. SomeBees
• ants_plans.py: Some additional logic for game setup
• ants_gui.py: The original GUI for Ants Vs. SomeBees
• gui.py: A new GUI for Ants Vs. SomeBees
• graphics.py: Utilities for displaying simple two-dimensional animations
• state.py: Abstraction for gamestate for gui.py
• utils.py: Some functions to facilitate the game interface
• ucb.py: Utility functions for CS 88
• assets: A directory of images and files used by gui.py
• img: A directory of images used by ants_gui.py
• ok: The autograder
• proj2.ok: The ok configuration file
• tests: A directory of tests used by ok
• mytests.rst: A space for you to add your custom tests; see section on adding your own tests

You can obtain all the files needed for this project by downloading this zip archive.

Logistics

This is a project. You may work with one other partner. You should not share your code with students who are not your partner or copy from anyone else's solutions.

In the end, you will submit one project for both partners. The project is worth 60 points.

The project is worth 60 points. 54 points are assigned for correctness, 4 point for submitting Phases 1-2 by the checkpoint date, and 2 points for the overall composition.

You will turn in the following files:

• ants.py
• mytests.rst (ungraded)

You do not need to modify or turn in any other files to complete the project. To submit the project, run the following command:

python3 ok --submit

You will be able to view your submissions on the Ok dashboard.

For the functions that we ask you to complete, there may be some initial code that we provide. If you would rather not use that code, feel free to delete it and start from scratch. You may also add new function definitions as you see fit.

However, please do not modify any other functions. Doing so may result in your code failing our autograder tests. Also, please do not change any function signatures (names, argument order, or number of arguments).

Testing

Throughout this project, you should be testing the correctness of your code. It is good practice to test often, so that it is easy to isolate any problems.

We have provided an autograder called ok to help you with testing your code and tracking your progress.

The primary purpose of ok is to test your implementations, but there is a catch. At first, the test cases are locked. To unlock tests, run the following command from your terminal:

python3 ok -u

This command will start an interactive prompt that looks like:

=====================================================================
Assignment: Ants Vs. SomeBees
OK, version ...
=====================================================================

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Unlocking tests

At each "? ", type what you would expect the output to be.
Type exit() to quit

---------------------------------------------------------------------
Question 0 > Suite 1 > Case 1
(cases remaining: 1)

>>> Code here
?

At the ?, you can type what you expect the output to be. If you are correct, then this test case will be available the next time you run the autograder.

The idea is to understand conceptually what your program should do first, before you start writing any code.

Once you have unlocked some tests and written some code, you can check the correctness of your program using the tests that you have unlocked:

python3 ok

Most of the time, you will want to focus on a particular question. Use the -q option as directed in the problems below.

The tests folder is used to store autograder tests, so make sure not to modify it. You may lose all your unlocking progress if you do. If you need to get a fresh copy, you can download the zip archive and copy it over, but you will need to start unlocking from scratch.

If you are ever stuck on a problem, you should add print statements to your code to help debug. Use print("DEBUG:", variable) to see the value of variable and still have your tests pass.

The Game

A game of Ants Vs. SomeBees consists of a series of turns. In each turn, new bees may enter the ant colony. Then, new ants are placed to defend their colony. Finally, all insects (ants, then bees) take individual actions. Bees either try to move toward the end of the tunnel or sting ants in their way. Ants perform a different action depending on their type, such as collecting more food, or throwing leaves at the bees. The game ends either when a bee reaches the ant queen (you lose), or the entire bee fleet has been vanquished (you win).

Core concepts

The Colony. This is where the game takes place. The colony consists of several places that are chained together to form a tunnel where bees can travel through. The colony has some quantity of food that can be expended to deploy ant troops.

Places. A place links to another place to form a tunnel. The player can place a single ant into each place. However, there can be many bees in a single place.

The Hive. This is the place where bees originate. Bees exit the beehive to enter the ant colony.

Ants. Ants are the usable troops in the game that the player places into the colony. Each type of ant takes a different action and requires a different amount of food to place. The two most basic ant types are the HarvesterAnt, which adds one food to the colony during each turn, and the ThrowerAnt, which throws a leaf at a bee each turn. You will be implementing many more.

Bees. Bees are the antagonistic troops in the game that the player must defend the colony from. Each turn, a bee either advances to the next place in the tunnel if no ant is in its way, or it stings the ant in its way. Bees win when at least one bee reaches the end of a tunnel.

Queen Ant: There is one queen ant in the whole colony. She is able to attack bees but she also has a special ability of fortifying the other ant troops. Bees can also win if they destroy the queen ant.

Core classes

The concepts described above each have a corresponding class that encapsulates the logic for that concept. Here is a summary of the main classes involved in this game:

• AntColony: Represents the colony and some state information about the game, including how much food is available, how much time has elapsed, where the QueenAnt resides, and all the Places in the game.
• Place: Represents a single place that holds insects. At most one Ant can be in a single place, but there can be many Bees. Place objects have an exit and an entrance which are also places. Bees travel through a tunnel by moving to a Place's exit.
• Hive: Represents the place where Bees start out.
• Insect: A superclass for Ant and Bee. All insects have an armor attribute, their remaining health, and a place attribute, the Place where they are currently located. Each turn, every active Insect in the game performs its action.
• Ant: Represents ants. Each Ant subclass has special attributes or a special action that distinguish it from other Ant types. For example, a HarvesterAnt gets food for the colony and a ThrowerAnt attacks Bees. Each ant type also has a food_cost attribute that indicates how much it costs to deploy one unit of that type of ant.
• Bee: Represents bees. Each turn, a bee either moves to the exit of its current Place if no ant blocks its path, or stings an ant that blocks its path.

Game Layout

Below is a visualization of an AntColony. As you work through the unlocking tests and problems, we recommend drawing out similar diagrams to help your understanding.

Playing the game

The game can be run in two modes: as a text-based game or using a graphical user interface (GUI). The game logic is the same in either case, but the GUI enforces a turn time limit that makes playing the game more exciting. The text-based interface is provided for debugging and development.

The files are separated according to these two modes. ants.py knows nothing of graphics or turn time limits.

To start a text-based game, run

python3 ants.py

To start a graphical game, run

python3 gui.py

To start an older version of the graphics, run

python3 ants_gui.py

When you start the graphical version, a new browser window should appear. In the starter implementation, you have unlimited food and your ants can only throw leaves at bees in their current Place. Try playing the game anyway! You'll need to place a lot of ThrowerAnts (the second type) in order to keep the bees from reaching your queen.

The game has several options that you will use throughout the project, which you can view with python3 ants.py --help.

usage: ants.py [-h] [-d DIFFICULTY] [-w] [--food FOOD]

Play Ants vs. SomeBees

optional arguments:
  -h, --help     show this help message and exit
  -d DIFFICULTY  sets difficulty of game (test/easy/medium/hard/extra-hard)
  -w, --water    loads a full layout with water
  --food FOOD    number of food to start with when testing

Your own test cases

Adding your own tests is entirely optional; you will not lose points if you submit an empty mytests.rst file.

We highly recommend that you add your own tests as you work through the project. It's a really helpful way to speed up the debugging process and improve your understanding of the code.

The course staff has also made an instructional video summarizing the information below.

Adding tests

Adding tests is easy. Directly edit the mytests.rst file included with the Ants project. We provide a sample structure to start from, but the test format is actually quite flexible. Here are some simple rules to follow:

• Follow standard Python doctest format. This is what we mostly use for the Ok tests, so feel free to use those as examples.
• For the most part, you may use whitespace as you'd like, but we recommend keeping it organized for your own sake.
• Generally, smaller, simpler tests will be more useful than larger, more complex tests.

You may also find our debugging guide helpful. If you're stuck on a particularly tricky Ok test case, a good first step would be to break it up into small parts and test them out yourself in mytests.rst.

Running tests

To run all your tests in mytests.rst with verbose results:

python3 ok -t -v

If you put your tests in a different file or split your tests up into multiple files:

python3 ok -t your_new_filename.rst

To run just the tests from suite 1 case 1 in mytests.rst:

python3 ok -t --suite 1 --case 1

You might have noticed that there's a "test coverage" percentage for your tests (note that coverage statistics are only returned when running all tests). This is a measure of your test's code coverage. If you're interested, you can find more information in our reference guide.

Phase 1: Basic gameplay

Important submission note: For full credit,

• Submit with Phases 1-2 complete by 4/18/21 (worth 4 pt).

In the first phase you will complete the implementation that will allow for basic gameplay with the two basic Ants: the HarvesterAnt and the ThrowerAnt.

Problem 0: Intro (0 pt)

Answer the following questions with your partner after you have read the entire ants.py file. If you cannot answer these questions, read the file again, consult the core concepts/classes sections above, or ask a question in the Question 0 thread on Piazza.

1. What is the significance of an insect's armor attribute? Does this value change? If so, how?
2. What are all of the attributes of the Insect class?
3. Is the armor attribute of the Ant class an instance attribute or class attribute? Why?
4. Is the damage attribute of an Ant subclass (such as ThrowerAnt) an instance attribute or class attribute? Why?
5. Which class do both Ant and Bee inherit from?
6. What do instances of Ant and instances of Bee have in common?
7. How many insects can be in a single Place at any given time (until Problem 9 is complete)?
8. What does a Bee do during its turn?
9. When does the game end?

You can test your understanding by running

python3 ok -q 00 -u

Problem 1: Food Cost (3 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 01 -u

First, add food costs and implement harvesters. Currently, there is no cost for deploying any type of Ant, and so there is no challenge to the game. You'll notice that Ant starts out with a base food_cost of zero. Override this value in each of the subclasses listed below with the correct costs.

Class	Food Cost	Armor
HarvesterAnt	2	1
ThrowerAnt	3	1

Now that deploying Ants cost food, we need to be able gather more food! To fix this issue, implement the HarvesterAnt class. A HarvesterAnt is a type of Ant that adds one food to the colony.food total as its action.

After writing code, test your implementation:

python3 ok -q 01

Try playing the game by running python3 gui.py. Once you have placed a HarvesterAnt, you should accumulate food each turn. You can also place ThrowerAnts, but you'll see that they can only attack bees that are in their Place, so it'll be a little difficult to win.

Problem 2: Place (6 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 02 -u

Complete the Place constructor by adding code that tracks entrances. Right now, a Place keeps track only of its exit. We would like a Place to keep track of its entrance as well. A Place needs to track only one entrance. Tracking entrances will be useful when an Ant needs to see what Bees are in front of it in the tunnel.

However, simply passing an entrance to a Place constructor will be problematic; we would need to have both the exit and the entrance before creating a Place! (It's a chicken or the egg problem.) To get around this problem, we will keep track of entrances in the following way instead. The Place constructor should specify that:

• A newly created Place always starts with its entrance as None.
• If the Place has an exit, then the exit's entrance is set to that Place.

Hint: Remember that when inside the definition of an __init__ method, the name self is bound to the newly created object.

Hint: Try drawing out two Places next to each other if things get confusing. In the GUI, a place's entrance is to its right while the exit is to its left.

After writing code, test your implementation:

python3 ok -q 02

Problem 3: ThrowerAnt (5 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 03 -u

In order for a ThrowerAnt to attack, it must know which bee it should hit. The provided implementation of the nearest_bee method in the ThrowerAnt class only allows them to hit bees in the same Place. Your job is to fix it so that a ThrowerAnt will throw_at the nearest bee in front of it that is not still in the Hive.

The nearest_bee method returns a random Bee from the nearest place that contains bees. Places are inspected in order by following their entrance attributes.

• Start from the current Place of the ThrowerAnt.
• For each place, return a random bee if there is any, or consider the next place that is stored as the current place's entrance.
• If there is no bee to attack, return None.

Hint: The random_or_none function provided in ants.py returns a random element of a sequence or None if the sequence is empty.

Hint: Having trouble visualizing the test cases? Try drawing them out on paper! The example diagram provided in Game Layout shows the first test case for this problem.

After writing code, test your implementation:

python3 ok -q 03

After implementing nearest_bee, a ThrowerAnt should be able to throw_at a Bee in front of it that is not still in the Hive. Make sure that your ants do the right thing! To start a game with ten food (for easy testing):

python3 gui.py --food 10

Phase 2: Ants!

Now that you've implemented basic gameplay with two types of Ants, let's add some flavor to the ways ants can attack bees. In this phase, you'll be implementing several different Ants with different offensive capabilities.

After you implement each Ant subclass in this section, you'll need to set its implemented attribute to True so that that type of ant will show up in the GUI. Feel free to try out the game with each new ant to test the functionality!

With your Phase 2 ants, try python3 gui.py -d easy to play against a full swarm of bees in a multi-tunnel layout and try -d normal, -d hard, or -d extra-hard if you want a real challenge! If the bees are too numerous to vanquish, you might need to create some new ants.

Problem 4: Long and Short Throwers (4 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 04 -u

The ThrowerAnt is a great offensive unit, but it'd be nice to have a cheaper unit that can throw. Implement two subclasses of ThrowerAnt that are less costly but have constraints on the distance they can throw:

• The LongThrower can only throw_at a Bee that is found after following at least 5 entrance transitions. It cannot hit Bees that are in the same Place as it or the first 4 Places in front of it. If there are two Bees, one too close to the LongThrower and the other within its range, the LongThrower should throw past the closer Bee, instead targeting the farther one, which is within its range.
• The ShortThrower can only throw_at a Bee that is found after following at most 3 entrance transitions. It cannot throw at any ants further than 3 Places in front of it.

Neither of these specialized throwers can throw_at a Bee that is exactly 4 Places away. Placing a single one of these (and no other ants) should never win a default game.

Class	Food Cost	Armor
ShortThrower	2	1
LongThrower	2	1

A good way to approach the implementation to ShortThrower and LongThrower is to have it inherit the nearest_bee method from the base ThrowerAnt class. The logic of choosing which bee a thrower ant will attack is essentially the same, except the ShortThrower and LongThrower ants have maximum and minimum ranges, respectively.

To implement these behaviors, you may need to modify the nearest_bee method to reference min_range and max_range attributes, and only return a bee that is in range.

The original ThrowerAnt has no minimum or maximum range, so make sure that its min_range and max_range attributes should reflect that. Then, implement the subclasses LongThrower and ShortThrower with appropriately constrained ranges and correct food costs.

Hint: float('inf') returns an infinite positive value represented as a float that can be compared with other numbers.

Don't forget to set the implemented class attribute of LongThrower and ShortThrower to True.

Note! Please make sure your variables are called max_range and min_range rather than maximum_range and minimum_range or something. The tests directly reference this variable name.

After writing code, test your implementation (rerun the tests for 03 to make sure they still work):

python3 ok -q 03
python3 ok -q 04

👩🏽‍💻👨🏿‍💻 Pair programming? Remember to alternate between driver and navigator roles! The driver controls the keyboard; the navigator watches, asks questions, and suggests ideas.

Problem 5: FireAnt (6 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 05 -u

Implement the FireAnt, which does damage when it receives damage. Specifically, if it is damaged by x armor units, and does not die, it does a damage of x to all bees in its place (reflected damage).

If it dies, it does an additional amount of damage, which is specified by its damage attribute (by default 3).

To implement this, we have to override the FireAnt's reduce_armor method. Normally, Insect.reduce_armor will decrement the insect's armor by the given amount and remove the insect from its place if armor reaches zero or lower. However, FireAnt also does damage to all the bees in its place when it receives damage, with a special bonus when its damage drops to 0, before being removed from its place.

Class	Food Cost	Armor
FireAnt	5	3

Hint: To damage a Bee, call the reduce_armor method inherited from Insect.

Hint: Damaging a bee may cause it to be removed from its place. If you iterate over a list, but change the contents of that list at the same time, you may not visit all the elements. This can be prevented by making a copy of the list. You can either use a list slice, or use the built-in list function.

 >>> lst = [1,2,3,4]
 >>> lst[:]
 [1, 2, 3, 4]
 >>> list(lst)
 [1, 2, 3, 4]
 >>> lst[:] is not lst and list(lst) is not lst
 True

Once you've finished implementing the FireAnt, give it a class attribute implemented with the value True.

Note, even though you are overriding the Insect.reduce_armor function, you can still use it in your implementation by calling it directly (rather than via self). Note that this is not recursion (why?)

After writing code, test your implementation:

python3 ok -q 05

You can also test your program by playing a game or two! A FireAnt should destroy all co-located Bees when it is stung. To start a game with ten food (for easy testing):

python3 gui.py --food 10

Problem 6: HungryAnt (5 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 06 -u

Implement the HungryAnt, which will select a random Bee from its place and eat it whole. After eating a Bee, it must spend 3 turns digesting before eating again. If there is no bee available to eat, it will do nothing.

Class	Food Cost	Armor
HungryAnt	4	1

Give HungryAnt a time_to_digest class attribute that holds the number of turns that it takes a HungryAnt to digest (default to 3). Also, give each HungryAnt an instance attribute digesting that counts the number of turns it has left to digest (default is 0, since it hasn't eaten anything at the beginning).

Implement the action method of the HungryAnt to check if it's digesting; if so, decrement its digesting counter. Otherwise, eat a random Bee in its place by reducing the Bee's armor to 0 and restart the digesting timer.

After writing code, test your implementation:

python3 ok -q 06

Problem 7: NinjaAnt (4 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 07 -u

Implement the NinjaAnt, which damages all Bees that pass by, but can never be stung.

Class	Food Cost	Armor
NinjaAnt	5	1

A NinjaAnt does not block the path of a Bee that flies by. To implement this behavior, first modify the Ant class to include a new class attribute blocks_path that is True by default. Set the value of blocks_path to False in the NinjaAnt class.

Second, modify the Bee's method blocked to return False if either there is no Ant in the Bee's place or if there is an Ant, but its blocks_path attribute is False. Now Bees will just fly past NinjaAnts.

Finally, we want to make the NinjaAnt damage all Bees that fly past. Implement the action method in NinjaAnt to reduce the armor of all Bees in the same place as the NinjaAnt by its damage attribute. Similar to the FireAnt, you must iterate over a list of bees that may change.

Hint: Having trouble visualizing the test cases? Try drawing them out on paper! See the example in Game Layout for help.

After writing code, test your implementation:

python3 ok -q 07

For a challenge, try to win a game using only HarvesterAnt and NinjaAnt.

Submission Reminder!

Phases 1 and 2 are due by 4/18/21 for 4 points.

Make sure to submit by the earlier deadline using the following command

python3 ok --submit

You can check to ensure that you have completed Phase 1-2's problems by running

python3 ok --score

Congratulations! You have finished Phases 1 and 2 of this project!

Phase 3: More Ants!

Important submission note: For full credit,

• Submit with Phases 3-4 complete by 4/29/21.

You will get 2 extra credit points for submitting the entire project by 4/27/21

We now have some great offensive troops to help vanquish the bees, but let's make sure we're also keeping our defensive efforts up. In this phase you will implement ants that have special defensive capabilities such as increased armor and the ability to protect other ants.

👩🏽‍💻👨🏿‍💻 Pair programming? Remember to alternate between driver and navigator roles! The driver controls the keyboard; the navigator watches, asks questions, and suggests ideas.

Problem 8: WallAnt (4 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 08 -u

We are going to add some protection to our glorious AntColony by implementing the WallAnt, which is an ant that does nothing each turn. A WallAnt is useful because it has a large armor value.

Class	Food Cost	Armor
WallAnt	4	4

Unlike with previous ants, we have not provided you with a class header. Implement the WallAnt class from scratch. Give it a class attribute name with the value 'Wall' (so that the graphics work) and a class attribute implemented with the value True (so that you can use it in a game).

After writing code, test your implementation:

python3 ok -q 08

Problem 9: Bodyguard Ant (8 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 09 -u

Right now, our ants are quite frail. We'd like to provide a way to help them last longer against the onslaught of the bees. Enter the BodyguardAnt.

Class	Food Cost	Armor
BodyguardAnt	4	2

A BodyguardAnt differs from a normal ant because it is a container; it can contain another ant and protect it, all in one Place. When a Bee stings the ant in a Place where one ant contains another, only the container is damaged. The ant inside the container can still perform its original action. If the container perishes, the contained ant still remains in the place (and can then be damaged).

Each BodyguardAnt has an instance attribute contained_ant that stores the ant it contains. It initially starts off as None, to indicate that no ant is being protected. Implement the contain_ant method so that it sets the bodyguard's contained_ant instance attribute to the passed in ant argument. Also implement the BodyguardAnt's action method to perform its contained_ant's action if it is currently containing an ant.

In addition, you will need to make the following modifications throughout your program so that a container and its contained ant can both occupy a place at the same time (a maximum of two ants per place), but only if exactly one is a container:

1. Add an Ant.is_container class attribute that indicates whether a subclass of Ant is a container. For all Ant instances, except for BodyguardAnt instances, is_container should be False. The BodyguardAnt.is_container attribute should be True.

2. Implement the method BodyguardAnt.can_contain which takes an other ant as an argument and returns True if:

   • This ant does not already contain another ant.
   • The other ant is not a container.

   Currently Ant.can_contain returns False by default; it needs to be overridden in BodyguardAnt

3. Modify Place.add_insect to allow a container and a non-container ant to occupy the same place according to the following rules:

   • If the ant currently occupying a Place can contain the insect (an Ant) passed to add_insect, then it does.
   • If the insect (an Ant) passed to add_insect can contain the ant currently occupying a Place, then it does. Also, set the Place's ant to be the container insect.
   • If neither Ant can contain the other, raise the same AssertionError as before (the one already present in the starter code).

After writing code, test your implementation:

python3 ok -q 09

Problem 10: TankAnt (3 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 10 -u

The BodyguardAnt provides great defense, but they say the best defense is a good offense. The TankAnt is a container that protects an ant in its place and also deals 1 damage to all bees in its place each turn.

Class	Food Cost	Armor
TankAnt	6	2

You should not need to modify any code outside of the TankAnt class. If you find yourself needing to make changes elsewhere, look for a way to write your code for the previous question such that it applies not just to BodyguardAnt and TankAnt objects, but to container ants in general.

After writing code, test your implementation:

python3 ok -q 10

👩🏽‍💻👨🏿‍💻 Pair programming? Remember to alternate between driver and navigator roles! The driver controls the keyboard; the navigator watches, asks questions, and suggests ideas.

Phase 4: Water and Might

In the final phase, you're going to add one last kick to the game by introducing a new type of place and new ants that are able to occupy this place. One of these ants is the most important ant of them all: the queen of the colony.

Problem 11: Water Place (3 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 11 -u

Let's add water to the colony! Currently there are only two types of places, the Hive and a basic Place. To make things more interesting, we're going to create a new type of Place called Water.

Only an ant that is watersafe can be deployed to a Water place. In order to determine whether an Insect is watersafe, add a new attribute to the Insect class named is_watersafe that is False by default. Since bees can fly, make their is_watersafe attribute True, overriding the default.

Now, implement the add_insect method for Water. First, add the insect to the place regardless of whether it is watersafe. Then, if the insect is not watersafe, reduce the insect's armor to 0. Do not repeat code from elsewhere in the program. Instead, use methods that have already been defined.

After writing code, test your implementation:

python3 ok -q 11

Once you've finished this problem, play a game that includes water. To access the wet_layout which includes water, add the --water option (or -w for short) when you start the game.

python3 gui.py --water

Problem 12 ScubaThrower (3 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q 12 -u

Currently there are no ants that can be placed on Water. Implement the ScubaThrower, which is a subclass of ThrowerAnt that is more costly and watersafe, but otherwise identical to its base class. A ScubaThrower should not lose its armor when placed in Water.

Class	Food Cost	Armor
ScubaThrower	6	1

We have not provided you with a class header. Implement the ScubaThrower class from scratch. Give it a class attribute name with the value 'Scuba' (so that the graphics work) and remember to set the class attribute implemented with the value True (so that you can use it in a game).

After writing code, test your implementation:

python3 ok -q 12

Extra Credit

Be warned that this extra credit problem can be very time-consuming!

During Office Hours and Project Parties, the staff will prioritize helping students with required questions. We will not be offering help with this question unless there are no other questions.

Queen Ant (2 pt)

Before writing any code, read the instructions and test your understanding of the problem:

python3 ok -q ec1 -u

Finally, implement the QueenAnt. The queen is a waterproof ScubaThrower that inspires her fellow ants through her bravery. The QueenAnt doubles the damage of all the ants behind her each time she performs an action. Once an ant's damage has been doubled, it is not doubled again for subsequent turns.

Note that the reflected damage of a fire ant should not be doubled, only the extra damage it deals when its armor is reduced to 0

Class	Food Cost	Armor
QueenAnt	7	1

However, with great power comes great responsibility. The QueenAnt is governed by three special rules:

1. If the queen ever has its armor reduced to 0, the bees win. The bees also still win if any bee reaches the end of a tunnel. You can call bees_win() to signal to the simulator that the game is over.
2. There can be only one true queen. Any queen instantiated beyond the first one is an impostor, and should have its armor reduced to 0 upon taking its first action, without doubling any ant's damage or throwing anything. If an impostor dies, the game should still continue as normal.
3. The true (first) queen cannot be removed. Attempts to remove the queen should have no effect (but should not cause an error). You will need to modify the remove_insect method of Place to enforce this condition.

Some hints:

• All instances of the same class share the same class attributes. How can you use this information to tell whether a QueenAnt instance is the true QueenAnt?
• You can find each Place in a tunnel behind the QueenAnt by starting at the ant's place.exit and then repeatedly following its exit. The exit of a Place at the end of a tunnel is None.
• To avoid doubling an ant's damage twice, keep track of all the ants who have been buffed in a way that persists across calls to QueenAnt.action.
• When buffing the ants' damage, keep in mind that there can be more than one ant in one place!
• Assume there can be only one game running at a time (so there can never be two true queen ants).

After writing code, test your implementation:

python3 ok -q ec1

Submission

Again, you will be turning in the following files:

• ants.py
• mytests.rst (ungraded)

Please run the following command to submit the project:

python3 ok --submit

You can check to ensure that you have completed all the problems by running

python3 ok --score

Then, go to your OK dashboard and verify that your submission was successful. You should see something like this:

You can click on the name of the assignment for more information about your submission. If you're experiencing issues with the autograder, remember that you can submit manually online.

Conclusion

You are now done with the project! If you haven't yet, you should try playing the game! There are two GUIs that you can use. The first is a new browser GUI that has fancy graphics and animations. The command to run it is:

python3 gui.py [-h] [-d DIFFICULTY] [-w] [--food FOOD]

The second is an older, but tried-and-true interface that we have been using over the past few years. The command to run it is:

python3 ants_gui.py [-h] [-d DIFFICULTY] [-w] [--food FOOD]

Acknowledgments: Tom Magrino and Eric Tzeng developed this project with John DeNero. Jessica Wan contributed the original artwork. Joy Jeng and Mark Miyashita invented the queen ant. Many others have contributed to the project as well!

Colin Schoen developed the new browser GUI. The beautiful new artwork was drawn by the efforts of Alana Tran, Andrew Huang, Emilee Chen, Jessie Salas, Jingyi Li, Katherine Xu, Meena Vempaty, Michelle Chang, and Ryan Davis.